Several diseases are thought to be caused by the abnormal folding and/or aggregation of disease-specific proteins. These proteins can accumulate into pathologically diagnostic accumulations, known as amyloids, which are visualized by certain histologic stains. Amyloids are thought to elicit inflammatory responses and have multiple negative consequences for the involved tissues. In addition, smaller aggregates of abnormally folded protein may exist and exert cytotoxic effects.
Medin, a 50 aa cleavage fragment of lactadherin/MFG-E8 is known to aggregate (e.g., undergo amyloidogenesis). Medin amyloid deposits are seen in patients with aortic aneurysms and in patients with Marfan syndrome. While the pathogenic nature of these aggregates is not fully understood, it is thought that medin may perturb smooth muscle cell function and thereby weaken the integrity of the aorta wall. Lactadherin and/or medin have also been implicated in pancreatitis, lupus, Alzheimer's disease and obesity.